Full Face Gasket vs Ring Gasket: What Is the Difference?
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26 Jul, 2026
Full Face Gasket vs Ring Gasket: What Is the Difference?
Choosing between a full face vs ring gasket isn’t just a preference. Get it wrong and you risk leaks, flange damage, or premature seal failure. The good news is that the selection logic is straightforward once you understand what each form is actually doing.
Quick Answer
A full-face gasket covers the entire flange surface, including bolt holes, and is designed for flat-face (FF) flanges.
A ring gasket sits only within the bolt circle, without bolt holes, and is designed for raised-face (RF) flanges.
Full-face gaskets distribute bolt load across the entire flange, making them better for brittle or low-pressure connections.
Ring gaskets concentrate sealing stress on a smaller area, delivering higher sealing performance in moderate to high-pressure systems.
Material choice (rubber, PTFE, graphite, fibre) applies to both forms and depends on temperature, pressure, and media.
Why Gasket Form Is So Important
A gasket works by filling in the tiny imperfections between two mating flange surfaces. When you tighten the bolts, the gasket compresses and conforms to both faces, creating a seal that stops fluid or gas from escaping.
But how well it seals depends on how much of the flange face the gasket actually covers. A raised face flange focuses all that bolt pressure onto a small central area, while a flat face flange spreads it across the whole surface. The gasket has to match that setup.
Use a ring gasket on a flat-face flange, and you’re only sealing a fraction of the surface area, which can cause uneven compression and risk cracking the flange, especially with brittle materials like cast iron. Use a full-face gasket on a raised-face flange, and it’ll still work, but with a larger sealing area, the compressive pressure per square millimetre drops.
The wrong gasket form leads to a compromised seal.
What Is a Full Face Gasket?
A full face gasket covers the entire face of the flange, right out to the outer edge, bolt holes and all. The holes in the gasket line up with the flange bolts, which also helps keep it properly aligned during installation.
Because it extends all the way to the edge, a full-face gasket has to be fitted with the joint fully taken apart. You can’t slip it in from the side. But that alignment from the bolt holes makes positioning easy and consistent.
Full-face gaskets are the standard choice for flat-face flanges, which are common in water systems, food and beverage plants, general pipework, and connections to cast iron or fibreglass components.
To order one, you’ll need the inside diameter, outside diameter, bolt circle diameter, number of bolt holes, and gasket thickness.
What Is a Ring Gasket?
A ring gasket sits inside the bolt circle; it doesn’t extend to cover the bolt holes. It seals only the raised portion in the centre of the flange, where the actual sealing contact occurs on a raised-face flange.
Because it covers less area, the same bolt load produces more concentrated sealing pressure. That’s what makes ring gaskets well-suited to moderate and higher-pressure applications. They also use less material, which generally makes them quicker and more cost-effective to produce.
You can also often install a ring gasket without fully disassembling the joint, since there are no bolt holes to thread through.
Ring gaskets are common in oil and gas, mining, chemical processing, and general industrial pipework – wherever raised-face flanges are used.
To order one, you need just three measurements: inside diameter, outside diameter, and thickness.
Full Face vs Ring Gasket: Side-by-Side
Full Face Gasket
Ring Gasket
Flange type
Flat face (FF)
Raised face (RF)
Bolt holes
Yes
No
Sealing area
Full flange face
Centre of flange only
Pressure suitability
Low to medium
Medium to high
Installation
Full disassembly required
Often drop-in without full disassembly
Measurements needed
ID, OD, bolt circle, bolt hole count, thickness
ID, OD, thickness
You can use a full-face gasket on a raised-face flange in a pinch. It won’t seal any worse, and the bolt holes help with positioning. But don’t go the other way. Using a ring gasket on a flat face flange leaves part of the flange unsupported, which can cause it to bend or crack under bolt load.
Which One Should You Use?
The type of flange you’re working with should make the decision for you:
Choose a full face gasket when:
Your flanges are flat face (FF)
You’re connecting to cast iron, fibreglass, or other materials that can’t handle uneven clamping force
The system runs at lower pressure
Choose a ring gasket when:
Your flanges are raised face (RF)
You need stronger sealing performance under moderate to high pressure
A quick, drop-in installation is useful
When neither option fits, custom gaskets are the practical answer.
Does Material Change Anything?
Both full-face and ring gaskets are available in the same range of materials. The form tells you where the gasket sits on the flange. The material tells you what conditions it can handle.
Common options available in both forms:
Rubber gaskets: EPDM, nitrile, neoprene, silicone, and Viton for water, steam, fuels, oils, and food-contact applications
PTFE: excellent chemical resistance for pharmaceutical and chemical processing
Compressed fibre (CNAF): reliable general-purpose option for moderate pressure and temperature
Graphite: handles high temperatures above 300°C in boilers, exhaust systems, and refinery applications
Spiral wound gaskets: semi-metallic construction for demanding high-pressure and high-temperature lines
Material selection comes down to your operating temperature, pressure, what’s flowing through the system, and any compliance requirements.
Get the Right Gasket from Industrial Experts
Industrial Experts is an Australian-owned gasket manufacturer and distributor based in Melbourne, supplying industrial gaskets across mining, food and beverage, oil and gas, wastewater, marine, and manufacturing sectors. Both full-face and ring gaskets are stocked in a wide range of materials across AS2129, AS4087, ASME/ANSI, and BS standards, from DN15 to DN1200.
Industrial Experts ships Australia-wide. Shipping times to all states are currently:
Small quantity: Same or next day (in-stock items ordered before 12pm dispatch same day)
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